While both the intensity and covariance quantities presented in the
Planck all-sky maps are, by definition, positive, there are situations
in which you will see negative values.
o In regards to the Planck intensity maps:
To begin with, the Planck...

The SMICA maps are multi-extension FITS files containing the CMB (in
the 1st extension) then the residuals at each band in the 2nd and 3rd
extensions. The CMB units are uK_CMB as stated in the headers. For
30-353 GHz the map residuals are map-CMB = for...

To uncompress the files you have downloaded from the command line,
type "unzip .zip". To uncompress multiple files at once, type "unzip
'*.zip'" (the single quotes are important), or "unzip \*.zip" -- you
just have to escape out the wildcard.
Double...

Here are some tips for making your large catalog search return
faster:
1. If you suspect that your query might return results larger than 2
Gb, you will need to break it up into smaller queries. It can be
difficult to predict the size of the returne...